The main objective of this dissertation was to study the emotional influences of odorants on subsequent brain activity. Emotions are complex mental states which occur as a reaction to external stimuli, and influence the subsequent processing of perceptual mechanisms in the brain. Odors in particular are thought to be very emotional stimuli due to the strong overlap which exists between brain areas associated with emotional responses, and brain areas responsible for the processing of odorants. At the behavioural level, both emotions and odors have been observed to have lingering effects on moods and performance in cognitive tasks, however the underlying mechanisms of these behavioural effects are not well understood. To study this question, we focused on the activity of the brain at rest after exposure to odors, as well as on the performance of very particular regions of interest during exposure to odors. We found significant changes in resting state network connectivity triggered by odorants, and these changes are distinct and characteristic as a function of perceived arousal or valence of the smell. Using state-of-the-art connectivity and pattern analyses in healthy populations, we observed emotional modulation in areas known to be involved in the perception of emotions and smells, as well as in regions part of the default mode network. We additionally used Representational Similarity Analyses to examine the specific roles that the amygdala, thalamus, and orbitofrontal cortex play in perceiving the valence and arousal of odorants. Our results have several potential implications, especially in the study of emotions. Understanding how valence and arousal impact the brain allows for us to better understand how it is that we react to stimuli, and what makes them emotional to us. The prolonged effects of smells can cause lingering behavioural effects, and understanding how changing functional connectivity is linked to this can help us understand how smells are processed, and what aspects of their processing contribute to their lingering effects (in particular, if their valence or arousal play a strong part in the observed changes in network connectivity). In summary, the studies described in this thesis propose new methods to study emotional effects of odorants, and emphasize the importance of this contribution to our growing knowledge of emotional stimuli and the brain.